1. Field of the Invention
The present invention relates to a method of manufacturing a ceramic multilayer circuit component including a ceramic multilayer circuit board, or a ceramic multilayer electronic component having a ceramic multilayer structure such as a hybrid IC, an LC composite part or a multilayer ceramic capacitor, and a handling apparatus for a ceramic green sheet which is advantageously employed in this method.
2. Description of the Background Art
FIGS. 12A to 12D show some steps which are included in a known method of manufacturing a ceramic multilayer circuit board as an exemplary ceramic multilayer circuit component.
First, a ceramic green sheet 2 is formed on a carrier film 1 of resin or the like by a doctor blade or the like as shown in FIG. 12A, and then dried. After such formation, the ceramic green sheet 2 may be cut into prescribed dimensions with the carrier film 1, if necessary.
Then, holes 3 for defining via holes are provided in the ceramic green sheet 2, which is still lined with the carrier film 1, by a punch or a drill, as shown in FIG. 12B. The holes 3 pass not only through the ceramic green sheet 2 but through the carrier film 1.
Then, conductor paste 4 is filled up in the respective holes 3 by screen printing or the like while forming wiring patterns 5 as shown in FIG. 12C, and then dried.
Then, the ceramic green sheet 2 is separated from the carrier film 1, and stacked on other ceramic green sheets 2 along prescribed order, as shown in FIG. 12D. More specifically, a suction head 7 which is enclosed with cutting edges 6 is employed. The cutting edges 6, which are vertically movable with respect to the suction head 7 within a prescribed range, are downwardly urged by a spring (not shown). Such a suction head 7 is reciprocative along arrow 8. On the other hand, the carrier film 1 which is provided with the ceramic green sheet 2 is placed on a suction stage 9.
The cutting edges 6 are first downwardly moved with the suction head 7 toward the ceramic green sheet 2 which is placed on the suction stage 9. At the same time, the cutting edges 6 define a kerf 10 in the ceramic green sheet 2. In this case, the cutting edges 6 may slightly penetrate into the carrier film 1. After the kerf 10 is defined, the suction head 7 attracts the ceramic green sheet 2, to separate the ceramic green sheet 2 from the carrier film 1 following upward movement thereof. Thereafter the suction head 7 is moved along arrow 8, to stack the ceramic green sheet 2 successively on other ceramic green sheets 2 in a prescribed position.
Thereafter a laminate 11 of the ceramic green sheets 2 obtained in the aforementioned manner is pressed and cut if necessary, and thereafter fired to provide a desired ceramic multilayer circuit board.
The aforementioned manufacturing method is applied not only to a ceramic multilayer circuit board, but to other ceramic multilayer circuit components. Such ceramic multilayer circuit components include an IC package 13 comprising a cavity 12, as shown in FIG. 13. In order to manufacture such an IC package 13 or the like, a method similar to that for the aforementioned ceramic multilayer circuit component is applied and a ceramic green sheet 2a which is already provided with a hole 14 for defining the cavity 12 as shown in FIG. 14 is employed in a step of successively stacking such ceramic green sheets. Conductive paths such as via holes and wiring patterns are omitted from FIGS. 13 and 14.
However, the ceramic green sheet provided with a hole for defining a cavity may encounter the following problems in handling, particularly when the same is separated from the carrier film:
First, the carrier film is indispensable for facilitating handling of a thin, i.e., mechanically soft ceramic green sheet of several 10 .mu.m in thickness, and for inhibiting the ceramic green sheet from crumpling and contraction dispersion in drying after filling of via holes with conductor paste or printing of wiring patterns. Consequently, the carrier film must be separated from the ceramic green sheet, before the ceramic green sheet is stacked on a plurality of other ceramic green sheets.
When the suction head 7 shown in FIG. 12D is applied to the ceramic green sheet 2a shown in FIG. 14 which is provided with the hole 14 for defining a cavity, however, it may be impossible to separate the ceramic green sheet 2a from a carrier film 1 due to insufficient suction. Further, the ceramic green sheet 2a which is provided with the hole 14 for defining a cavity is so mechanically soft that a corner portion of the hole 14 may be undesirably cut upon separation from the carrier film 1. In addition, the as-separated ceramic green sheet 2a may be crumpled when the same is attracted by the suction head 7.
The aforementioned problems caused in separation are not specific to the ceramic green sheet 2a shown in FIG. 14, which is provided with the hole 14 for defining a cavity. When an extremely thin ceramic green sheet of not more than 10 .mu.m in thickness is employed or large force is required for separating a ceramic green sheet from a carrier film, for example, the ceramic green sheet may be hard to separate or the as-separated ceramic green sheet may be crumpled, even if the ceramic green sheet is provided with no hole for defining a cavity. Therefore, the problems in separation are also serious in manufacturing of a miniature ceramic multilayer circuit component, which must have high accuracy in stacking of ceramic green sheets.